Transformer



Aug. 3 {1926. 1,594,701

I C. M. WELCH TRANSFORIER Filed August 26, 1921 Patented Aug. 3, 1926.

CHARLES H. WELCH, OF OGDEN, ARKANSAS.

TRANSFORMER.

Application filed August 26, 1921. Serial No. 495,522.

The object of my invention is to secure a directed settling of water and foreign matter from the body of insulating fluid ad jacent an electrical device, and means foi isolating the precipitated fluidity substance from the insulating fluid proper.

The invention will hereinafter be more particularly described as embodied in an improved fluid insulated electrical transformer. In this apparatus, water may be introduced into the fluid by a number of causes, chief among which is condensation from the atmosphere under change of temperature. The presence of water in the insulating fluid, is a series menace to the device, since it, may be carried by the convecting fluid to points of potential difference, resulting in insulation break down.

The specifications, drawings and claims set forth herein what I believe to be the points of novelty in my present invention, and whereas other arrangements and modifications may be made, I intend to cover all such arrangements and modifications which do not depart from the spirit and scope of m invention.

eferring to the drawings: similar letters refer to similar parts throughout the views in which:

Fig. 1, represents a top view of thecasing of a fluid insulated transformer. Fig. 2, represents the transformer in section showing the arrangement of the various parts in relation to the invention.

In Fig. 1, is shown a fluid insulated electrical transformer; with a top cover piece A, an enclosing drum container B, pole hanger hook C, supporting lug D, terminal outlet pipe E, case fitting F, insulating block G, low tension terminal H, lifting ring I. high tension terminal outlet opening J, removable fluid inlet plu K, top annular flange L, drum annular ange M, clamping bolts N, core and coil frame 0, core and coil frame supports P, core Q, coils R, core clamps S, fluid outlet plug T, annular drain shelf U, casing bottom V, opening in shelf W, and an annular compartment X.

Electrical devices of the fluid insulated type are commonly filled with oil. When t e active elements of the device are at rest, or, are not throwing off suflicient heat to agitate the fluid by convection circulation, any water in the fluid will settle by gravity to a lower level. I The insulating fluid may be free from water proper, and yet hold water vapor in suspension. 'While there is no affinity between water and oil, I have experimented with the peculiar aflinity of vapor and oil. During periods when the device is under load and high temperature, water vapor may rise from the fluid and condense against points of cool surface forming water drops inside the container. These water drops drip into the fluid and gravi tate to the bottom of the container.

When water or other heavy matter in the insulating fluid gravitates through the fluid medium, the shelf or baflle U provides a drain through the opening TV. The bottom V forms the compartment X between the bottom and the shelf or baflle. The watery fluid like substance contains much dangerous matter in solution and suspension such as sulphur, acid, alkali, carbon, metal dust, and the like, which are as dangerous to electrical insulation as water; and all of which is therefore confined and practically isolated in the space or compartment X from the main body of insulating fluid surrounding the device. This fluidity substance may be drained off or washed out at intervals through the outlet plug T, which plug T closes a vent to the atmosphere.

But while the action of my'improvement secures adirected settling of the insulating fluid as hereinbefore described, its primary function is to prevent carrying the settlings of precipitated matter by circulation of the fluid to points of danger to the device. In this latter connection, it is obvious the funnel shaped baflie U interferes with fluid from below rising above the battle plate info the region surrounding the device. And moreover, the bafl'le U also prevents the fluid from above from flowing freely by convection into the region below the baiiie plate.

I have demonstrated by experiment that F transformers in service on distribution lines contain much water and foreign matter in the insulating oil. Settlings occur in the bottom of the cases when the transformers are not loaded, but when the load is on these settlings are washed by the circulating oil into the oil ducts in the coils where the water is absorbed by the insulation and the windings are plastered with material which prevents free radiation of heat and increases the leakage and hazard of breakdown. In this connection, the simplicity and cheapness of my improved construction renders it convenient to install during the manufacture of sheet metal containing cases. Under service conditions, my improvement reduces the energ losses of the transformer with consequent increase in capacity rating for the device, and it also insures a longer life to the insulation.

I find in the case of small high voltage transi orn'iers v'here insulating fluid of high power desired, that I am ab e to lreep the oil around the coils in a dr state because the small ount of moisture condensing near the sur .cc of the fluid is precipitated to the bottom where it is isolated from dangerous pro nitv to the active elements through the me ium of in improvement.

As before pointed out, my invention con sists in providing a shelf or battle having an opening adjacent the bottom of the casing forming a compartment hav g an outlet, whereb the object tlCCtYillPll led in securing gravity settling of the fluid into the compartmentand prevention ()1 circulating back into the i surrounding the device: hence I form the b'alile so that portions are adapted to receive and direct the drainage of the scttlines through the opening into the compartment JOlOW and prevent free circulation between the fluid in the compartment and the heated fluid surrounding the device.

The described tunnel shaped batle is the best means known to me at this time for the settlings;

carrying the invention into etlect. in my claims annexed to and lornnng a part o't this specification, 1 do not desire to be restricted in the choice of material construction except as defined by my said claims.

What I claim is:

1. The combination with a fluid insulated electrical device, a casing therefor, a shell adjacent the bottom of the casing having portions adapted to drain the fluid, a compartment formed by the said shell and the bottom oi the casing, and an pening through the said shelf communicating between the said compartment and the fluid surrounding the said device.

The combination with a fluid insulated electrical device, a casing therefor, a shelf adjacent the bottom of the casing havin portions adapted to receive and direct the drainage of the settlings from the fluid, an

opening through the said shell draining the said settlings, and a con'ipartment formed by the said shelf and the bottom of the easing into which the said settlingstrom the fluid are drained.

The combination with a fluid insulated electrical device, a casing therefor, a ballie adjacent the bottom of the casing forming a compartment with the said bottom of the using. an opening into the said compartment through the said ballle, and portions of the said bati'le adapted to prevent lrce circulation between the heated fluid surrounding the device and the fluid in the said compartn'ient.

*l. The combination with a fluid insulated electrical device, a casing therefor, bafile having an opening adjacent the bottom of the *asing, a compartment formed by the said battleand the bottom of the casing, the said opening connnunicating between the fluid surrounding the device and the said compartment, the said baflle being formed to receive and direct the drainage of precipitated watery settlings from the fluid surrounding the said device through the said opening nto the. said compartment, portions of the battle adapted to prevent free circulation between the heated fluid surrounding the device and the said watery precipitatedflnid in the said compartment, and a means in the said compartment for outlet of fluid.

The combination with a fluid insulated electrical device, a casing therefor, ai'unnel sha )ed balile plate inside the casing adjacentthe lower portion thereof, a hole in the said bafl'le plate through which the fluid may drain, and a means below the said ballle plate for outlet of fluid from the casing.

6. The combination with a fluid insulated electrical device, a casing therefor: a funnel shaped battle plate luwing an opening adjacent the bottom of the container and formin g a compartment. whereb the free circulation of the heated fluid adjacent the said electrical device and the fluid within the compartment is prevented, and a means in the said compartment for outlet of fluid.

In testimony I affix my signature at Ogden, Arkansas, August- 22, 1921.

CHARLES M. lVELCH. 

